Tooth implant arrangement

ABSTRACT

A tooth implant arrangement has an implant body which can be inserted in a jaw or jawbone and a structural member which can be detachably secured to the implant body by means of a bolt-like mounting element, and on which a cap, a replacement crown or the like can be placed and secured. The structural member is mounted so as to be resiliently movable relative to the implant body in the axial and/or the sagittal directions. The mobility of a tooth implant arrangement of this type in the jaw or jawbone is comparable to that of a natural tooth.

FIELD OF THE INVENTION

The present invention relates to a tooth implant arrangement with animplant body which can be inserted in a jaw and with a structural bodywhich is held, preferably releasably, on the implant body by means of abolt-like holding element, and which is seated elastically movable inthe axial and sagittal direction with respect to the implant body withthe aid of an elastic seating ling. A firing cap, a bridge element, acrown replacement or the like can be put and fixed in place.

BACKGROUND OF THE INVENTION

In a known tooth implant arrangement, such as is known as the so-calledHa-Ti implantation system, the structural body is rigidly connected withthe implant body, which is rigidly implanted in the lower or upper jaws,by means of a bolt-like holding element embodied as a screw, in such away that the structural body is inserted with its inner end into acorresponding bore of the implant body and that the fastening screwembedded in the structural body is securely tightened. Since the bridgeelement or crown replacement or the like fastened thereon is alsomaintained in place on the structural body by means of a fixation screw,the entire tooth implant arrangement is quasi immovably fixed in thelower or upper jaw. This is in contrast to natural teeth, which can atleast perform a certain axial elastic movement within the jaw.Furthermore, the incisors are additionally elastically movable in asagittal direction within certain limits within the jaws. This rigidholding of the known tooth implant arrangement in the jawbone results,among other things, in that persons which suffer from bruxism, i.e.grind their teeth at night in particular, cannot be provided with suchtooth implant arrangements. The known rigid tooth implant arrangement,which is, so to speak, fixedly cemented in the jawbone, can furthermorelead to damage, in particular of the bridge element, crown replacementor the like, in persons who do not tend to grind their teeth.

A crown fastening arrangement for an implant to be placed in the jaws,essentially has a bolt part in the structural body and essentiallypenetrates it is provided with a screw head, and the other bolt part,which is maintained over a defined longitudinal area in the implantbody, and is provided with an exterior wall, is known from DE-C-34 13811, wherein a connecting piece is fixedly screwed to the implant body,on whose spreadable barrel-shaped head a crown connecting piece isplaced, which is supported on the front ring side on the connectingpiece via an elastic ring. Although this arrangement permits movementbetween the crown and the implant body, this movement can neither bedefined nor reproduced. Since rotational security is also not provided,an uncontrolled three-dimensional mobility of the crown connecting pieceis the result. Thus a mobility which could be compared with a naturaltooth is not provided, particularly since a movement generally resultsfrom a load, and not mainly from a wrong or excessive load. The knownarrangement not only results in a low primary stability, but also in anunrealistic structural height, particularly because of the connectingpiece.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a toothimplant arrangement of the type mentioned at the outset, which has amobility in the jaw or jawbone comparable to a natural tooth, and has asimple structure.

This object in connection with a tooth implant arrangement of the typementioned at the outset is characterized by the bolt-like holdingelement between the structural body and the implant body. Two bolt partsare provided which are connected via a pivot shafi with each other.

By means of the steps in accordance with the present invention, thetooth implant arrangement is provided with mobility within the lower orupper jaws similar to that of natural teeth, along with an optimalprimary stability. Thus, a tooth implant arrangement of this type can beused in more varied ways and it is subjected only to a small measure towear and possible damage.

An advantageous embodiment of the holding element is characterized inthat the bolt part, disposed in the structural body and essentiallypenetrates it, is provided with a screw head, and the other bolt part,which is maintained over the defined longitudinal area in the implantbody is provided with an exterior thread.

A further embodiment of the present invention is characterized in thatthe spring-elastic mobility of the structural body can be adjusted inrelation to the implant body, which means that it is possible to makethe possible or allowable movement paths of the tooth implant devicewith respect to the jaw adjustable for compensating the occurring axialand/or sagittal force effects. In other words, it is possible to presetthe elastic mobility of the tooth implant device to suit the patient.

A preferred embodiment with respect to the structural design of therelative mobility between the structural body and the implant bodyresults from an elastic ring, preferably in the form of an O-shapedseating ring disposed on an axial front face of the structural body andon a circumferential surface of the implant body, and a firing cap, orthe like, supported on the elastic ring, located approximately oppositethe implant body. Here the option of setting the size of the deflectionor mobility is predetermined in a simple manner.

In a practical manner, the pivot shaft of the holding element isarranged approximately at the level of the elastic ring inside thestructural body. This provides for the suitable mobility of thestructural body with respect to the implant body.

In order to assure a movement of the structural body with respect to theimplant body in only one direction, the structural body is embodied onits end extending into the implant body, in the shape of a universalball joint with appositely located flattened side areas. By means ofthis the rotation as well as a lateral movement of a tooth of the toothimplant arrangement around its axis or in relation to adjoining naturalor artificial teeth is prevented. In this case it is practical to employa gap between the universal ball joint surface of the end part of thestructural body and that of a recess in the implant body.

A secure fixation of a firing cap, a crown replacement or the like onthe structural body is assured by means at least one orally insertedfixation pin and/or by two parallel fixation pins, which are providedwith threaded sections, and have been inserted into blind bores which atleast partially penetrate the structural body. A seal from the exteriorto the interior is also provided, when the firing cap is seated with anaxial prestress on the axial ring are provided.

By means of equipping the firing cap with a tooth veneer and/or byprefabricating the filing cap it is possible to avoid the separateproduction of the firing cap in every individual case.

Further details of the invention can be taken from the followingdescription, in which the invention is described in more detail andexplained by means of the exemplary embodiments represented in thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1, is a longitudinal section, arranged parallel with the frontalside, through a tooth implant device in accordance with a firstexemplary embodiment of the present invention,

FIG. 2, is a longitudinal section, rotated by 90° in relation to thesectional plane in FIG. 1, through the tooth implant device in FIG. 1,and

FIG. 3, is a longitudinal section, corresponding to FIG. 2, through atooth implant arrangement in accordance with a second embodiment of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

To compensate for the occurring axial and/or sagittal force effects, thetooth implant arrangement 10 or 10' showing in FIG. 1 is constructed insuch a way that it permits a relative mobility, which can be adjusted inits stiffness and its possible paths, of the artificial tooth in thedirection of the arrows A and/or B with respect to the jaw or theportion of the tooth implant arrangement fixed in place in the jawbone.

In accordance with FIGS. 1 and 2, the tooth implant arrangement 10 hasan implant body 11, which is implanted in a sketched-in bone 12 of alower or upper jaw. Implanting of the implant body 11 is possible invarious known ways, for example in that the implant body 11 has anexterior thread, not represented, with the aid of which it can bescrewed into a correspondingly pre-drilled blind bore in the respectivejawbone. Further than that, the implant body 11 has a concentricinterior threaded bore 14. The exterior circumference of the implantbody 11 can be respectively shaped cylindrical or slightly conical. Aswill be described later, on its end projecting out of the jawbone 12,the implant 11 has an annular throat 16 on its front for receiving anelastic seating ring 17. The implant body 11 is provided with aslit-like recess 18, which is concentric with the annular throat 16 andwhose bottom 19 is embodied semi-cylindrically.

A structural body 21, which is embodied to be hollow, is placed on theupper end of the implant body 11 projecting out of the jawbone 12, whosecylindrical through-bore 22 extends on its upper end from an annularrecess 23 of larger diameter and makes a transition on its lower endinto a recess 24 which widens conically in a plane. The structural body21 essentially has a cylindrical shape, whose front, facing away fromthe implant body 11 is flat, and whose end section, facing the implantbody 11 is embodied semi-cylindrically with parallel flat lateral areas26. A circumferential groove 29, which has a throat-like diameter and inwhich the elastic seating ring 17 is maintained, is embodied between theaxially cylindrical part 27 and the end part 28, which issemi-cylindrical in the transverse direction.

The structural body 21 is inserted with its lower semicylindrical endpart 28 into the correspondingly shaped recess 18 of the implant body 11and is maintained in such a way that there is no lateral play betweenthe semi-cylindrical end part 28 of the structural body 21 and therecess 18 of the implant body 11, but that there is a sufficient gap 30in the axial direction.

The structural body 21 is fastened on the implant body 11 with the aidof an articulated screw 31. The articulated screw 31 has an upper part32 inserted into the through-bore 22 of the structural body 21, and alower exterior-threaded part 33, which can be screwed into the implantbody 11, both of which parts are hingedly connected with each other viaan axial pin 34. On their facing rounded ends, through which the axialpin 34 extends, the two respectively cylindrical parts 32 and 33 engageeach other in the manner of a groove and strip connection, as can beseen in FIG. 1. In this way it is possible to pivot these two parts 32and 33 in relation to each other in a defined plane. The upper part 32has a screw head 36, which is arranged, partially embedded in theannular recess 23 of the structural body 21, and is sealed by means ofan 0-ring 37 in the exemplary embodiment. The head 36 has a slit or thelike for applying a turning tool. The articulated screw 31 for fasteningthe structural body 21 on the implant body 11 is screwed into theinterior threaded bore 14 of the implant body 11 in such a way that theaxial pin 34 is arranged parallel with the axis of the semi-cylindricalbottom 19 of the recess 18, or parallel with the frontal side of thestructural body 21, so that a movement of the structural body 21 ispossible in relation to the implant body 11 in the sagittal direction orthe direction of the oral cavity, but not toward the neighboring teeth.This sagittal mobility of the structural body 21 is resiliently elastic,since the structural body 21 is supported on the front side of theimplant body 11 via the elastic seating ring 17.

Depending on the tightening moment applied to the articulated screw 31when fastening the structural body 21 on the implant body 11, theseating ring 17 is more or less compressed, and a greater or lesserprestress of the elastic seating ring 17 is achieved in this way. Thismeans that, as a function of the size of the prestress, on the one handthe force to be applied for deflecting the structural body 21 withrespect to the implant body 11 is adjustable and, on the other hand, theamount of mobility, i.e. the degree of deflection of the structural body21 with respect to the implant body 11, can be set. For this reason thegap 30 must also be of a sufficiently large size in the axial direction.The axial pin 34 should be approximately arranged in such a way that itscenter axis is equal to the cylinder axis of both the semi-cylindricalpart 28 of the structural body 21 and of the circular base surface 19 ofthe recess 18 of the implant body 11. The position of the axial pin 34approximately at the level of the hollow-throat-like annular groove 29on the structural body 21 is preferred. The mobility of the structuralbody 21 in the direction toward the oral cavity and with the oppositedirection with respect to the lower part 33 of the articulated screw 31is assured by the recess 24,.conical in one plane, in the path of thethrough-bore 22 in the area of the far side of the axial pin 34 andfacing the implant body 11, as can be seen from FIG. 2.

In the exemplary embodiment represented, the implant body 11 and thestructural body 21 are made of an aluminum oxide ceramic material. It isunderstood that the one and/or the other body 11, 21 can also be made ofother materials used in tooth implantation, for example atitanium-coated composite material. Similar conditions apply to thearticulated screw 31. The elastic seating ring 17 is made of ahygienically unobjectionable elastic plastic material, such as silicon.

A firing cap 41 has been placed over the structural body 21 and theupper area of the articulated screw 31 which, like the implant body 11,the structural body 21 and the articulated screw 34, can beprefabricated for certain types of teeth. The firing cap 41, whoseexterior circumference is at least partially embodied in the manner of atooth crown, has a centered, stepped blind bore recess 42 extending fromthe interior, in which the head 36 of the articulated screw 31 and thecylindrical part 27 of the structural body 21 are received. The frontedge 43 of the firing cap 41 facing the implant body 11 rests with itsannular throat 44 on the elastic seating ring 17. From the direction ofthe oral side, the firing cap 41 and the structural body 21 are providedwith two parallel, obliquely inwardly directed bores 46, which have athreaded section only in the oral area of the firing cap 41 and intowhich two parallel transversal pins 47, which are provided with athreaded section, can be inserted or screwed for fixing the firing cap41 in place on the structural body 21. The two bores 46 are blind boreswhich terminate in the frontal area of the firing cap 41, are located ata radial distance from the articulated screw 31 and which, in the areaof the structural body 21, are both located in the latter as well as inthe firing cap 41. The firing cap 41 which, for example, is made of analuminum oxide ceramic material, can be placed in the correct positionon the structural body 21 by means of a tongue-and-groove connection 49.During assembly it is achieved by means of pressure on the firing cap 41against the elastic seating ring 17 that the individual bore elements ofthe bores 46 are aligned for the simple oral insertion of the pin 47.

A patient-specific tooth veneer 51 is provided on the prefabricatedfiring cap 41, which is fastened by firing it on the latter. With theexemplary embodiment represented, the tooth veneer 51 has the form of afrontal incisor.

The tooth implant arrangement 10' represented in FIG. 3 is basicallystructured the same as the tooth implant arrangement 10, so that in therepresentation of FIG. 3 the individual components, without beingindividually mentioned, are identified by the same reference numerals,but provided with a dash. A difference between the tooth implantarrangement 10' with respect to the tooth implant arrangement 10essentially lies in the design of the structural body 21 which as awhole has a larger volume and is asymetrically embodied at the expenseof the firing cap 41, wherein the head 36' of the articulated screw 31'is altogether embedded in the structural body 21. Furthermore, athreaded bore 48', which is in axial alignment with the through-bore 46'provided in the firing cap 41', has been provided in the structural body21' for receiving a single transversal screw 47', whose head is disposedcompletely embedded in the firing cap 41'. Furthermore, in thestructural body 21'the lower part 28' is embodied to be hemisphericalwith flattened sides located opposite each other. Similar applies to theshape of the recess 18' of the implant body 11'.

It is understood that the firing cap 41 or 41' can also receive aportion of a bridge in case of several adjoining implant arrangements,or a crown or the like in place of a tooth veneer for an individualartificial tooth.

I claim:
 1. A tooth implant arrangement, comprising:an implant body forinsertion in a jaw or jawbone; a structural body held on said implantbody; a bolt-like holding element for holding said structural body onsaid implant body; an elastic seating ling mounted to both saidstructural body and said implant body situated so that when saidstructural body is held by said implant body by said bolt-like holdingelement said structural body is seated elastically movable in the axialand sagittal direction with respect to said implant body; and one of afiring cap, a bridge element and a crown replacement are held on saidstructural part, wherein said bolt-like holding element comprises twobolt parts and a pivot shaft connecting said two bolt parts.
 2. Thetooth implant arrangement as defined in claim 1, wherein one of said twobolt pats includes a screw head and the other bolt part, which extendsover a defined longitudinal area of said implant body, includes anexterior thread.
 3. The tooth implant arrangement as defined in claim 2,wherein said at least one of a firing cap, a bridge and a crownreplacement is supported on said elastic seating ring.
 4. The toothimplant arrangement as defined in claim 3, wherein said firing cap isseated on said elastic seating ring under an axial pretension.
 5. Thetooth implant arrangement as defined in claim 2, wherein said pivotshaft is situated inside of said structural body at approximately thelevel of said elastic seating ring.
 6. The tooth implant arrangement asdefined in claim 2, wherein said structural body has one end whichextends into said implant body, said one-end being embodied in the shapeof a universal ball joint with oppositely located flattened side areas.7. The tooth implant arrangement as defined in claim 6, wherein saidimplant body defines a recess, and wherein a gap is formed between thesurface of said universal ball joint and said recess.
 8. The toothimplant arrangement as defined in claim 2, further comprising:an orallyinserted fixation pin, wherein said one of a firing cap, a bridge and acrown replacement is held to said structural body by said orallyinserted fixation pin.
 9. The tooth implant arrangement as defined inclaim 8, wherein said structural body includes two blind bores, andwherein two parallel fixation pins are provided, each having a threadedsection inserted into a respective one of said blind bores.
 10. Thetooth implant arrangement as defined in claim 1, wherein saidelastically movable seating is adjustable relative to said implant body.11. The tooth implant arrangement as defined in claim 1, wherein saidimplant body defines a circumferential surface and said structural bodydefines an axial front face, and wherein said elastic seating ringcomprises an O-shaped seating ring situated between said axial frontface and said circumferential surface.
 12. The tooth implant arrangementas defined in claim 1, wherein said firing cap includes a tooth veneer.13. The tooth implant arrangement as defined in claim 1, wherein saidfiring cap is a prefabricated component.